Research Papers: Alternative Energy Sources

Wind Tower System With a Helical Wind Deflecting Structure, Computational Fluid Dynamics, and Experimental Studies

[+] Author and Article Information
Majid Rashidi

Cleveland State University,
Cleveland, OH 44115
e-mail: m.rashidi@csuohio.edu

Jaikrishnan R. Kadambi

Case Western Reserve University,
Cleveland, OH 44106
e-mail: jrkadambi@case.edu

David Kerze

Gorman-Lavelle Corporation,
Cleveland, OH 44127
e-mail: dkerze@Gorman_Lavelle.com

Contributed by the Advanced Energy Systems Division of ASME for publication in the Journal of Energy Resources Technology. Manuscript received April 22, 2013; final manuscript received July 23, 2013; published online October 17, 2013. Editor: Hameed Metghalchi.

J. Energy Resour. Technol 136(2), 021202 (Oct 17, 2013) (7 pages) Paper No: JERT-13-1135; doi: 10.1115/1.4025409 History: Received April 22, 2013; Revised July 23, 2013

A wind tower system having a three dimensional heliacal wind deflecting structure is studies in this work. The purpose of the helical structure is to increase the natural wind speed and direct the follow of the wind toward two columns of horizontal-axis rooftop-size wind turbines that are installed in the grooves of the helical structure, diametrically opposed to each other. Computational fluid dynamics analyses were conducted to determine the influence of the helical structure on the wind speed reaching the turbines. A wind speed amplification coefficient was determined for a helical structure of 6.7 m outer diameter. The velocity profiles of the wind flow around the helical structure were determined under a postulated wind speed of 4.47 m/s. The flow was modeled as turbulent with a Reynolds Number of 2,052,167. Standard “k–ε” turbulent model with “near wall treatment” and “standard wall function” were adapted in all analysis. A “y+” value of 50 was held constant in all simulation. The grid-size effects on the accuracy of the results were examined. Convergence criterion was satisfied in each case. This study shows that the helical structure having an outer diameter of 6.7 m results in an average wind speed increase factor of 1.52. An experimental wind tower system was fabricated and installed at an elevation of 40 m above the ground. The wind tower system comprised of four identical rooftop size wind turbines, each having 1.6 KW name-plate-rating. A helical wind deflecting structure of 11 m tall, and 7 m in major diameter was used in fabrication of the tower. An active yaw-control mechanism was used to orient the tower into the prevailing wind. The experimental results show that as the result of the use of the wind deflecting structure, an average power amplification factor of 4.69 was obtained for the tower, in comparison with the standard standalone installation of the four wind turbines.

Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.


Energy Information Administration, Official Energy Statistics From the U.S. Government, 2007, p. 1
Ainslie, J. F., 1988, “Calculating the Flow Field in the Wake of Wind Turbines,” J. Wind Eng. Ind. Aerodyn., 27, pp. 213–224. [CrossRef]
Katic, I., Hojstrup, J., and Jensen, N. O., 1986, “A Simple Model for Cluster Efficiency in European Wind Energy Association,” Rome.
Cao, H., 2001, “Aerodynamics Analysis of Small Horizontal Axis Wind Turbine Blades by Using 2D and 3D CFD Modeling”, MS thesis, University of Central Lancashire, http://clok.uclan.ac.uk/2399/1/CaoH_final_thesis.pdf.
Chalothorn, T., and Tawit, C., 2009, “Optimal Angle of Attack for Untwisted Blade Wind Turbine,” Renew. Energy, 34(5), pp. 1279–1284.
Grant, A., Johnstone, C., and Kelly, N., 2008, “Urban Wind Energy Conversion: The Potential of Ducted Wind Turbine,” Int. J. Renew. Energy, 33(6), pp. 1157–1163. [CrossRef]
Nema, P., Nema, R. K., and Rangnekar, S., 2009, “A Current and Future State of the Art Hybrid Energy System Using Wind and PV–Solar: A Review,” J. Renew. Sustain. Energy Rev., pp. 2096–2013. [CrossRef]
Zhoou, W., Lou, C., Li, Z., Lu, L., and Yang, H., 2010, “Current Status of Research on Optimum Sizing of Standalone Hybrid Solar-Wind Power Generation Systems,” Appl. Energy, 87(2), pp. 380–389. [CrossRef]
Uzarraga-Rodriguez, Cristobal, N., Gallegos-Munoz, A., and Riesco Avila, J. M., 2011, “Numerical Analysis of a Rooftop Vertical Axis Wind Turbine,” Proceeding of the ASME 2011 International Conference on Energy Sustainability, August 7–10, 2011, Washington, DC, USA, pp. 2061–2070.
Ayhan, D., and Saglam, S., 2012, “A Technical Review of Building-Mounted Wind Power Systems and a Sample Simulation Model,” J. Renew. Sustain. Energy Rev., 16(1), pp. 1040–1049. [CrossRef]
Suma, A. B., Ferraro, R. M., Dano, B., and Moonen, S. P. G., 2012, “Integrated Roof Wind Energy System,” EPJ Web of Conferences, 33, p. 03002. [CrossRef]
Saeidi, D., Sedaghat, A., Alamdari, P., and Alemrajabi, A. A., 2013, “Aerodynamic Design and Economical Evaluation of Site Specific Small Vertical Axis Wind Turbines,” J. Appl. Energy, 101, pp. 765–775. [CrossRef]
Ahmed, N. A., 2013, “A Novel Small Scale Efficient Wind Turbine for Power Generation,” J. Renew. Energy, 57, pp. 79–85. [CrossRef]
Kulkarni, A., and Moeykens, S., 2005. Flow Over a Cylinder. Retrieved October 17, 2006, from Fluent [FlowLab 1.2]. http://flowlab.fluent.com/exercise/pdfs/cylinder.pdf


Grahic Jump Location
Fig. 1

An innovative wind tower with a helical shape wind deflecting structure

Grahic Jump Location
Fig. 2

A front view of the tower

Grahic Jump Location
Fig. 3

A longitudinal cross-section of the tower

Grahic Jump Location
Fig. 4

Stationary steel structure for supporting of the yaw-able wind-deflecting shell

Grahic Jump Location
Fig. 5

Construction of the helical structure from multitude of the same panel

Grahic Jump Location
Fig. 6

Domain sizing; (Kulkarni and Moeykens [6])

Grahic Jump Location
Fig. 7

2D cylinder under inviscid flow regime

Grahic Jump Location
Fig. 8

2D cylinder, structured grid, entire domain

Grahic Jump Location
Fig. 9

Close-up of the 2D cylinder, structured grid

Grahic Jump Location
Fig. 10

2D cylinder, scaled residuals (inviscid flow)

Grahic Jump Location
Fig. 11

Structured to unstructured grid transition

Grahic Jump Location
Fig. 12

Close-up of the unstructured grid

Grahic Jump Location
Fig. 13

Elevation details of the unstructured grid

Grahic Jump Location
Fig. 14

Velocity magnitude on a longitudinal plane intersecting the tower (k–ε turbulence model)

Grahic Jump Location
Fig. 15

Velocity magnitude on a transverse plane intersecting the tower (k–ε turbulence model)

Grahic Jump Location
Fig. 16

Velocity distribution across a 2-m diameter window in the wind speed amplified zone

Grahic Jump Location
Fig. 17

A picture of the experimental set up

Grahic Jump Location
Fig. 18

Power Curve of a typical the wind turbine for a standalone installation



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In